Walsh Cut (alluvial placer)

Mine, Probably inactive

Commodities and mineralogy

Main commodities Au
Other commodities Ag; Pb; W; Sb
Ore minerals arsenopyrite; galena; gold; scheelite; scorodite; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale NM
Quadrangle map, 1:63,360-scale C-1
Latitude 64.6118
Longitude -165.4172
Nearby scientific data Find additional scientific data near this location
Location and accuracy This gold-bearing alluvial fan is at the mouth of Walsh Cut (NM214), south of Sophie Gulch (NM208). The fan is as much as 500 feet long and as much as 300 feet across. Most of the fan is covered with vegetation typical of adjacent hill slopes, but the lower, sparsely vegetated fan resulted from placer mining operations at Walsh Cut (NM214). The lower fan extends almost to Rock Creek. The map site is in the north-central part of section 23, T. 10 S., R. 34 W., Kateel River Meridian. The location is accurate.

Geologic setting

Geologic description

Two distinct alluvial fans have formed below the mouth of Walsh Cut (NM214). The lower fan resulted from hydraulic operations in Walsh Cut. The upper and larger fan is covered with soil and vegetation. It could have formed in part from placer mining operations, but also from natural erosion of a residual placer that was later mined in Walsh Cut. Quartz boulders locally crop out in the upper fan. These boulders contain sulfides, principally arsenopyrite and more rarely galena and stibnite. They probably also contain scheelite. The upper fan extends between elevations of 230 and 320 feet and is as much as 300 feet across; it is about 450 feet long. The lower manmade fan extends between elevations of 205 and 230 feet and is as much as 250 feet across. It is only sparsely vegetated and contains abundant boulders and cobbles of quartz and sulfides. Soil samples collected from the fans locally exceed 1 ppm gold and are strongly anomalous in arsenic and other metals.
Geologic map unit (-165.419807307053, 64.6110345270805)
Mineral deposit model Alluvial placer Au (Cox and Singer, 1986; model 39a).
Mineral deposit model number 39a
Age of mineralization Holocene.

Production and reserves

Workings or exploration The core of the older deposit could have formed from the erosion of a residual placer upslope at Walsh Cut. The lower and younger fan probably formed soon after World War II.
Indication of production None
Reserve estimates There is a low-grade resource of gold and other metals in the fan deposits.

References

MRDS Number 10307998
Reporters C.C. Hawley and Travis L. Hudson
Last report date 7/10/2000